Intracluster gas velocity gradients have been recently detected by the authors in the Centaurus cluster ( Abell 3526 ) using the Doppler shift of X-ray spectral lines with ASCA Solid-state Imaging Spectrometers .
The velocity gradient was found to be maximum along a line roughly perpendicular to the direction of the incoming subgroup Cen 45 and has a correspondent velocity difference of \sim 3.4 \pm 1.1 \times 10 ^ { 3 } km s ^ { -1 } within a \sim 10 ^ { \prime } -diameter region centered on the cD galaxy NGC 4696 .
Such bulk velocities should Comptonize the Cosmic Microwave Background Radiation producing variations of intensity and temperature that can be detectable in the near future with bolometers such as BOLOCAM .
In this paper we realistically estimate the expected CMBR Comptonization for the central region of Abell 3526 , using ASCA and ROSAT data to constrain the S-Z parameter expectations .